The use of fuel cells in vehicles for providing a plurality of different tasks, such as supplying electrical energy, water, nitrogen-enriched air and heat is a known approach to provide an improved fuel efficiency, reduced emissions and a decreased noise emanation. Especially, the use of fuel cells in aircraft has a great potential for clearly reducing the fuel consumption and emissions and in replacing auxiliary power units based on gas turbine engines.
Hybrid gas turbine engines that are a combination of common gas turbine engines and fuel cell devices are a further approach to increase the overall efficiency of the power supply to an aircraft by integrating solid oxide fuel cell units directly into a gas turbine engine in or at a combustion chamber of the gas turbine. For example, DE 10 2011 018 448 A1 discloses a hybrid gas turbine engine with solid oxide fuel cell units that are located upstream of a combustion chamber of a gas turbine and are supplied with a hydrocarbon gas turbine fuel directly reformed inside the fuel cell units. The operation of these solid oxide fuel cell units thereby depends on the operation of the gas turbine engine and is mainly focused on the supply of electrical energy.